Throughout the specification the term xe2x80x9cpylonxe2x80x9d shall be taken as comprising an elongate element which may be disposed at any angle with respect to the horizontal axis and which may be located in a terrestrial, aquatic or marine environment. The term shall also be taken to include struts and interconnecting members which may be provided between columns and the like for support.
The present invention comprises a development of the underwater servicing device which is the subject of PCT/AU92/00160 which has application to the servicing and treatment of surfaces such as ships hulls dam walls and the like, but is limited in its application in regard to the surfaces of pylons because of the degree of curvature of those surfaces. In the past the underwater surfaces of pylons have been inspected and serviced by divers which is hazardous and very labour intensive and presents significant difficulties in regard to deep water installations.
It is an object of the present invention to provide a pylon servicing apparatus which is capable of traversing the length of a pylon to enable the suite of the pylon to be treated. In addition the apparatus of the invention need not be restricted to use in an underwater environment
Accordingly the invention resides in a pylon servicing means comprising a carriage having a first drive means provided on the carriage, said first drive means being adapted to engage the pylon to enable the carriage to be moved longitudinally along the pylon, the carriage supporting a housing which can be received around a pylon, the housing defining a space, said housing having two opposed end walls and at least one side wall extending between the end walls, the end walls having inner edges being configured to be receivable about the pylon, said housing being divided axially into at least two portions which are pivotally interconnected to be movable between a closed position defining said space and an open position, a second drive means provided between the portions to enable the movement between the open and closed position, wherein when the portions are in the closed position they can cooperate with the pylon to form an annular space surrounding the portion of the length of the pylon located between the end faces and when in the open position the housing can be moved into and out of engagement with the pylon, a first sealing means provided on the inner edge of each end wall and adapted to be sealingly engageable with the pylon when the portions are in the closed position and a second sealing means provided on at least one of the abutting edges of each portion and adapted to be sealingly engageable with the adjacent portion when the portions are in the closed position.
According to a preferred feature of the invention the first sealing means are selectively movable into and out of sealing engagement with the pylon when the portions are in the closed position.
According to a further preferred feature of the invention the pylon servicing means is capable of being used with a pylon where a portion of the pylon is underwater. According to further preferred feature the pylon servicing means further comprises an evacuation means adapted to pump water-from the annular space, a valve means adapted to be controllable to permit the entry of water into the annular space and a ventilation means adapted to permit the entry of air into the space.
According to a preferred feature of the invention the space accommodates a servicing means adapted to treat the surface of the pylon accommodated by the annular space. According to a further preferred feature the servicing means is provided with a surveying means which is capable of enabling the surface of the pylon to be surveyed remotely. According to a particular embodiment the surveying means comprises a remotely controlled camera and/or a non-destructive testing means.
According to a further preferred feature of the invention the servicing means comprises a head member which is capable of moving circumferentially around the annular space and longitudinally through the annular space. According to a further preferred feature, a control means adapted to cause said circular and longitudinal movement of the head member in a controlled manner. According to one embodiment of the invention the head member is capable of directing a high pressure fluid blast onto the surface of the pylon. The fluid blast may include abrasive particulate materials entrained in the fluid flow. It is a further feature of the embodiment that the head member is capable of applying a coating to the surface of the pylon. According to various forms of the embodiment of the invention the coating can comprise a sealant, a paint composition, a grouting composition, concrete or any combination of such. It is a further feature of the embodiment that the head member is capable of directing a ted gaseous flow onto the surface of the pylon. It is a further feature of the embodiment that the servicing head includes the means of remotely inspecting and surveying the surface which means may comprise a camera and/or a non-destructive testing means.
According to a further preferred feature of the invention said first drive means comprises a set of driven wheels supported from the carriage which are moveable radially into and out of engagement with the pylon. According to one embodiment of the invention when the driven wheels are out of engagement with the pylon and the portions are in the open position the carriage can be moved radially into and out of engagement with the pylon and longitudinally along the pylon and when the driven wheels are in engagement with the pylon the carriage is only capable of longitudinal movement along a pylon. It is preferable that the second drive means is operable independently of the first drive means. It is a further preferred feature of the embodiment that the driven wheels are not able to cause longitudinal movement of the carriage on the pylon when the first sealing means is in engagement with the pylon.
According to the further preferred feature of the invention the carriage is provided with a thruster means adapted to be capable of being activated to cause movement through water, said thruster applying a force to the carriage which can be transverse and/or parallel to the central axis of the housing.
According to a further preferred feature of the invention the carriage is associated with a ballast means which is associated with a means for delivering water and air into the ballast means to vary the buoyancy of the apparatus between positive, neutral and negative buoyancy.
According to a further preferred feature of the invention the housing has a generally cylindrical shape when the portions are in the closed position.
The invention will be more fully understood in the light of the following description of several specific embodiments.